Erectile dysfunction

My partner suffers with erectile dysfunction. He struggles to get an erection, when he does we can’t change positions and it’s very temperamental. I love him dearly, I’ve been with him for 7years. And now trying for a baby. Does anyone have any experience with there partners in this department, any advice please! I have tried everything physically/sexually possible. In the process with doctors, tried viagra, also he’s on statin for high cholesterol. Thanks xx